1. Field of the Invention
The present invention relates to delivery of content over a broadcast network and in particular to a broadband digital broadcast network.
2. Description of the Prior Art
As is well known, broadband digital broadcast (BDB) networks, such as the terrestrial Digital Video Broadcast (DVB-T) network, are intended to deliver content in the form of a television broadcast and can also deliver data in a multicast/unicast. The delivery of data and indeed any other service as a multicast or unicast requires the presence of some form of conditional access to ensure the content reaches the correct terminal. Furthermore, to provide interactivity, it is necessary to provide a return channel linking a terminal to the network. In this way, a request for content can be communicated to the network which may subsequently deliver the content to the terminal.
It has thus been the case that content has been delivered either at the request of the receiving terminal or at the instigation of the network. In the latter case, the network might receive a request from an external content provider to deliver content in the form of an advertisement or the like over the network. Such a request might lead to the content being broadcast, multicast, or even unicast. However, the decision for a content provider as to how and when to request the delivery of content is hampered by the unidirectional nature of the network.